by Amy Huxtable, University of Sheffield Production of isopeptide-bonded BoNT molecules.(A) Schematic of the structural organization of BoNT/A (upper panel) with additions of the SpyCatcher elements to two botulinum parts (lower panel). (B) Coomassie-stained SDS–PAGE showing the purified proteins and spontaneous assembly of isopeptide-bonded BoNT. (C) Coomassie-stained SDS–PAGE showing isolation of iBoNT from the unreacted excess...